Large-scale graphene transfer in ultra-high vacuum and design of a low temperature ultra-high vacuum scanning tunneling microscope

Graphene;Scanning tunneling microscopy;Dry contact transfer;Low temperature scanning tunneling microscope

Liu, Ximeng ; Lyding ; Joseph W.

关键词: Graphene;    Scanning tunneling microscopy;    Dry contact transfer;    Low temperature scanning tunneling microscope;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/50627/Ximeng_Liu.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

This thesis documents a way of transferring large-scale graphene onto clean surfaces in an ultra-high vacuum scanning tunneling microscope chamber via a modified direct contact transfer method. A polyethylene terephthalate (PET) film was chosen as the material for supporting graphene during the in-situ transfer. Both a scanning electron microscope and an atomic force microscope were used to characterize the transferred graphene quality. This is the first demonstration of successfully transferring large-scale graphene in the ultra-high vacuum environment, which opens a lot of opportunities for studying the properties of pristine graphene and graphene-substrate interactions.Secondly, this thesis also documents an ongoing design and construction of a low temperature, ultra-high vacuum scanning tunneling microscope. A novel cooling mechanism was implemented in our design which includes a closed-cycle refrigerator in order to enable longer experiment durations and reduced costs of operation. So far we are able to reach a temperature of ~30 K with the STM scanner, vibration isolation and all electronic connections installed. We believe that this can be further improved by making some minor modifications to our design as our future work in order to reach our goal of operating at a temperature of <10 K.